1. Field of the Invention
The present invention relates to a method and apparatus for treating waste or residual materials which can be utilized energetically, and more particularly to a method and apparatus for treating refuse from light-duty shredders, which, having been reduced in size and classified, are stored in bunkers and fed into an electric arc furnace for incineration.
2. Description of the Related Art
In processing consumer goods, it is desirable to produce the smallest possible quantity of residue or waste. It is further desirable to produce waste that can be disposed of easily. The objective is, if possible, to process residues or wastes in such a way that increasingly large quantities can be recycled.
Special requirements are posed in recycling used automobiles, for example. Compared to discarded machinery and equipment from old industrial sites, ships and railroad facilities, used automobiles contain an especially high percentage of non-metallic materials such as plastic, glass, rubber, textiles, lacquer, oil and grease, along with metal coatings such as tin and zinc, and non-ferrous metal components such as cobalt, copper and chrome. In standard processing aggregates, i.e. shears, presses and shredders, it is possible to deliberately produce particular bulk densities of recyclable material.
One method of processing a given portion of residue or waste containing a percentage of lighter-weight shredder residue is to produce a plastic granulate and inject the granulate into a blast furnace or cupola furnace. When this is done, the portion of the residue making up the percentage of lighter-weight shredder residue or waste material must first be ground at high expense into a granule smaller than 4 mm. The plastic portion of the residue or waste must then be separated out and injected in the area of the blast-tuyere level of a blast furnace at temperatures of approximately 2000.degree. C. This method is not only expensive, but also recycles only a relatively small portion of residual materials.